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      <title>Dubbo 的服务治理功能有哪些？如何进行服务治理？ - 交互式测验</title>
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      </style>
    </head>
    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>Dubbo 的服务治理功能有哪些？如何进行服务治理？ - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
                    <div class="progress-bar">
                        <div id="progress-indicator"></div>
                    </div>
                    <div id="question-container">
                      <p id="question-text"></p>
                      <ul class="options-list" id="options-list"></ul>
                    </div>
                    <div id="result-container"></div>
                    <div id="hint-container" class="hint-container"></div>
                </div>
                <div class="quiz-footer" id="quiz-footer">
                  <button id="prev-btn" class="nav-btn">上一题</button>
                  <button id="hint-btn" class="nav-btn" style="background-color: #ffc107; color: #333; box-shadow: 0 4px 12px rgba(255,193,7,0.3);">提示</button>
                  <button id="next-btn" class="nav-btn">下一题</button>
                </div>
            </div>
          </div>
      </div>

      <script>
        const quizData = [
  {
    "question": "在 Dubbo 的服务治理体系中，像 Zookeeper 或 Nacos 这样的服务注册中心扮演的核心角色是什么？",
    "options": [
      "直接处理和转发服务消费者与提供者之间的远程过程调用（RPC）请求。",
      "持久化存储每一次服务调用的事务日志，用于故障恢复。",
      "管理服务提供者的注册信息，并允许服务消费者动态地发现这些服务。",
      "执行服务提供者的核心业务逻辑，确保代码正确运行。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "服务注册中心的核心职责是作为服务提供者和服务消费者之间的“目录服务”。提供者启动时将自己的地址和元数据注册到中心，消费者则从中心查询并获取这些信息，从而实现服务间的解耦和动态发现。",
    "source": "文档中「1. 服务注册与发现」部分",
    "hint": "文档提到，服务提供者将自己注册到注册中心，以便消费者能够'发现并调用'。"
  },
  {
    "question": "根据文档描述，以下哪一项不属于 Dubbo 内置的负载均衡策略？",
    "options": [
      "随机 (Random)",
      "最快响应优先 (Fastest Response)",
      "加权随机 (Weighted Random)",
      "轮询 (Round Robin)"
    ],
    "correctAnswerIndex": 1,
    "explanation": "文档中明确列出了 Dubbo 提供的内置负载均衡策略，包括轮询（Round Robin）、随机（Random）、加权轮询（Weighted Round Robin）和加权随机（Weighted Random）等。“最快响应优先”虽然是一种常见的负载均衡思想，但在该文档中并未被列为 Dubbo 的内置策略之一。",
    "source": "文档中「2. 负载均衡」部分",
    "hint": "请仔细阅读文档中关于'内置策略'的列表，看看哪一个选项不在其中。"
  },
  {
    "question": "在 Dubbo 的容错处理机制中，“失败转移 (Failover)” 的主要作用是什么？",
    "options": [
      "向服务消费者返回一个预设的、简化的默认值或模拟数据。",
      "在同一个失败的实例上反复尝试，直到调用成功或达到重试次数上限。",
      "当某个服务实例调用失败且不可用时，自动将请求切换到其他可用的实例上。",
      "为了保护系统，暂时阻止所有对该服务的后续请求。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "失败转移（Failover）是容错处理的一种策略。它的核心思想是，当一次调用失败后，框架会尝试调用集群中的另一个节点，以提高服务的整体可用性。这与在同一节点上重试（Retry）是不同的机制。",
    "source": "文档中「3. 容错处理」部分",
    "hint": "文档描述失败转移是当某个服务实例'不可用'时，自动将请求转移到'其他可用'的服务实例。"
  },
  {
    "question": "根据文档，什么情况会触发熔断机制，从而切断对故障服务的调用？",
    "options": [
      "当服务提供者的 CPU 或内存使用率达到告警线时。",
      "当服务的错误率超过预设的阈值时。",
      "当服务正在进行灰度发布，部分流量被切换到新版本时。",
      "当检测到服务消费者与提供者之间的网络延迟突然增大时。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "熔断机制的核心是监控服务的健康状况，通常通过统计一段时间内的调用成功率或错误率。当错误率达到或超过一个设定的阈值时，熔断器会“跳闸”（打开），在接下来的一段时间内直接拒绝所有对该服务的调用，从而保护整个系统免受雪崩效应的影响。",
    "source": "文档中「5. 熔断」部分",
    "hint": "文档中提到熔断机制的配置与服务的'错误率'有关。"
  },
  {
    "question": "如文档所述，在 Dubbo 服务治理中使用动态配置中心（如 Nacos、Apollo）带来的主要好处是什么？",
    "options": [
      "保证了所有服务实例的运行时间达到100%，杜绝任何宕机可能。",
      "可以自动根据实时流量来增加或减少服务实例的数量。",
      "能够对服务消费者和提供者之间的所有通信内容进行加密。",
      "可以在不重启服务的情况下，实时更新和应用新的配置。"
    ],
    "correctAnswerIndex": 3,
    "explanation": "动态配置中心实现了配置与代码的分离。通过配置中心，运维或开发人员可以随时修改服务的参数（如超时时间、负载均衡策略等），这些变更会被实时推送到正在运行的服务实例上并生效，即“配置热更新”，极大地提高了运维效率和灵活性。",
    "source": "文档中「6. 动态配置」部分",
    "hint": "该功能的核心优势在于'配置热更新'，即无需重启服务即可应用新配置。"
  },
  {
    "question": "当系统负载过高或非核心服务出现故障时，“服务降级”策略的主要目标是什么？",
    "options": [
      "自动将所有用户请求重定向到一个静态的“系统维护中”页面。",
      "立即停止整个系统，防止数据不一致。",
      "通过返回默认值或调用备用服务，来保证核心功能的稳定运行。",
      "触发告警，通知运维人员立即手动修复故障服务。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "服务降级是一种“丢车保帅”的策略。在系统资源紧张或依赖的服务不可用时，为了保证核心业务流程不受影响，可以暂时牺牲一些非核心功能，为其提供一个简化的、预设的响应。这确保了系统在极端情况下的基本可用性。",
    "source": "文档中「9. 服务降级」部分",
    "hint": "思考一下当服务调用失败时，降级策略会如何处理返回结果，其目的是为了保证'核心功能正常运行'。"
  },
  {
    "question": "在 Dubbo 众多服务治理功能中，哪一个机制的核心目标是“防止故障扩散”，通过在服务持续异常时暂时隔离该服务？",
    "options": [
      "服务降级 (Service Degradation)",
      "动态配置 (Dynamic Configuration)",
      "负载均衡 (Load Balancing)",
      "熔断 (Circuit Breaking)"
    ],
    "correctAnswerIndex": 3,
    "explanation": "熔断机制就像电路中的保险丝。当一个服务（下游依赖）持续出现问题时，熔断器会“断开”连接，调用方在一段时间内不再请求这个不健康的服务，而是直接快速失败或执行降级逻辑。这可以防止对故障服务的无效调用耗尽调用方的资源，从而避免了故障的连锁反应，即“故障扩散”。",
    "source": "文档中「5. 熔断」部分",
    "hint": "文档中直接描述了这个机制的功能是'及时切断对故障服务的调用，防止故障扩散'。"
  }
];
        console.log("Quiz Data:", JSON.parse(JSON.stringify(quizData))); // 添加这行用于调试，以可展开的JSON格式输出
        
        let currentQuestionIndex = 0;
        let score = 0;
        // 存储每个问题的回答状态
        const userAnswers = new Array(quizData.length).fill(null); 

        const questionTextEl = document.getElementById('question-text');
        const optionsListEl = document.getElementById('options-list');
        const resultContainerEl = document.getElementById('result-container');
        const quizContentEl = document.getElementById('quiz-content');
        const progressIndicatorEl = document.getElementById('progress-indicator');
        const prevBtn = document.getElementById('prev-btn');
        const nextBtn = document.getElementById('next-btn');
        const hintBtn = document.getElementById('hint-btn');
        const hintContainerEl = document.getElementById('hint-container');

        function loadQuestion() {
          resultContainerEl.innerHTML = '';
          optionsListEl.innerHTML = '';
          hintContainerEl.style.display = 'none'; // 隐藏提示
          
          if (currentQuestionIndex >= quizData.length) {
            showFinalScore();
            return;
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          const currentQuestion = quizData[currentQuestionIndex];
          questionTextEl.textContent = `(${currentQuestionIndex + 1}/${quizData.length}) ${currentQuestion.question}`;
          
          currentQuestion.options.forEach((optionText, index) => {
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            li.className = 'option-item';
            li.textContent = optionText;
            li.dataset.index = index; // Store index in a data attribute
            // 如果这道题已经回答过，恢复状态
            if (userAnswers[currentQuestionIndex] !== null) {
                if (index === userAnswers[currentQuestionIndex]) {
                    li.classList.add('selected');
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            }
            optionsListEl.appendChild(li);
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          // 如果已经回答过，直接显示结果
          if (userAnswers[currentQuestionIndex] !== null) {
              const isCorrect = userAnswers[currentQuestionIndex] === currentQuestion.correctAnswerIndex;
              showResult(isCorrect, currentQuestion);
          }
          
          updateNavigationButtons();
          updateProgress();
        }

        function selectOption(optionIndex) {
            userAnswers[currentQuestionIndex] = optionIndex;
            const currentQuestion = quizData[currentQuestionIndex];
            const isCorrect = optionIndex === currentQuestion.correctAnswerIndex;

            // 重新计算分数
            score = userAnswers.reduce((acc, answer, index) => {
                return answer === quizData[index].correctAnswerIndex ? acc + 1 : acc;
            }, 0);

            showResult(isCorrect, currentQuestion);
            updateNavigationButtons();
        }
        
        function updateProgress() {
            const answeredQuestions = userAnswers.filter(answer => answer !== null).length;
            const progressPercentage = (answeredQuestions / quizData.length) * 100;
            progressIndicatorEl.style.width = `${progressPercentage}%`;
        }
        
        function updateNavigationButtons() {
            prevBtn.style.display = 'block';
            nextBtn.style.display = 'block';
            hintBtn.style.display = 'block'; // 显示提示按钮

            prevBtn.disabled = currentQuestionIndex === 0;
            nextBtn.disabled = false; // 最后一题时，下一题按钮不禁用，而是用于显示报告
            nextBtn.textContent = (currentQuestionIndex === quizData.length - 1) ? '查看报告' : '下一题';
            
            // 如果当前问题没有提示，则禁用提示按钮并隐藏提示内容
            if (!quizData[currentQuestionIndex].hint) {
                hintBtn.disabled = true;
                hintContainerEl.style.display = 'none';
                hintContainerEl.textContent = ''; // 清除旧的提示内容
            } else {
                hintBtn.disabled = false;
            }
        }

        function showResult(isCorrect, questionData) {
            resultContainerEl.innerHTML = ''; // 清空之前的结果
            const resultBox = document.createElement('div');
            resultBox.className = `result-box ${isCorrect ? 'correct' : 'incorrect'}`;
            
            let html = `<h3>${isCorrect ? '回答正确！' : '回答错误'}</h3>`;
            if (!isCorrect) {
                html += `<p><strong>正确答案是：</strong> ${questionData.options[questionData.correctAnswerIndex]}</p>`;
            }
            html += `<div class="explanation-text">${questionData.explanation}</div>`;
            html += `<div class="source-text">来源: ${questionData.source}</div>`;
            
            resultBox.innerHTML = html;
            resultContainerEl.appendChild(resultBox);

            // 禁用所有选项的点击事件，并高亮正确/错误答案
            Array.from(optionsListEl.children).forEach((child, index) => {
                child.style.pointerEvents = 'none';
                // 高亮正确答案
                if (index === questionData.correctAnswerIndex) {
                    child.classList.add('correct'); // 需要添加CSS样式
                    child.style.backgroundColor = '#d4edda';
                    child.style.borderColor = '#c3e6cb';
                }
                // 如果选错了，高亮错误选项
                if (!isCorrect && index === userAnswers[currentQuestionIndex]) {
                    child.classList.add('incorrect'); // 需要添加CSS样式
                    child.style.backgroundColor = '#f8d7da';
                    child.style.borderColor = '#f5c6cb';
                }
            });
        }

        function goToNextQuestion() {
            if (currentQuestionIndex < quizData.length - 1) {
                currentQuestionIndex++;
                loadQuestion();
            } else {
                showFinalScore();
            }
        }

        function goToPreviousQuestion() {
            if (currentQuestionIndex > 0) {
                currentQuestionIndex--;
                loadQuestion();
            }
        }
        
        function showHint() {
            const currentQuestion = quizData[currentQuestionIndex];
            if (currentQuestion.hint) {
                hintContainerEl.textContent = currentQuestion.hint;
                hintContainerEl.style.display = 'block';
            } else {
                hintContainerEl.style.display = 'none';
            }
        }

        function showFinalScore() {
            document.querySelector('.quiz-body').style.display = 'none';
            document.getElementById('quiz-footer').style.display = 'none';

            const correctCount = score;
            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  